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Posted to commits@commons.apache.org by tn...@apache.org on 2012/07/14 23:36:26 UTC
svn commit: r1361590 -
/commons/proper/collections/trunk/src/main/java/org/apache/commons/collections/ListUtils.java
Author: tn
Date: Sat Jul 14 21:36:25 2012
New Revision: 1361590
URL: http://svn.apache.org/viewvc?rev=1361590&view=rev
Log:
[COLLECTIONS-421] Cleanup of ListUtils, use wildcards for hashCodeForList, use generic example in javadoc, thanks to Benedikt Ritter.
Modified:
commons/proper/collections/trunk/src/main/java/org/apache/commons/collections/ListUtils.java
Modified: commons/proper/collections/trunk/src/main/java/org/apache/commons/collections/ListUtils.java
URL: http://svn.apache.org/viewvc/commons/proper/collections/trunk/src/main/java/org/apache/commons/collections/ListUtils.java?rev=1361590&r1=1361589&r2=1361590&view=diff
==============================================================================
--- commons/proper/collections/trunk/src/main/java/org/apache/commons/collections/ListUtils.java (original)
+++ commons/proper/collections/trunk/src/main/java/org/apache/commons/collections/ListUtils.java Sat Jul 14 21:36:25 2012
@@ -35,15 +35,7 @@ import org.apache.commons.collections.li
* Provides utility methods and decorators for {@link List} instances.
*
* @since Commons Collections 1.0
- * @version $Revision$
- *
- * @author Federico Barbieri
- * @author Peter Donald
- * @author Paul Jack
- * @author Stephen Colebourne
- * @author Neil O'Toole
- * @author Matthew Hawthorne
- * @author Dave Meikle
+ * @version $Id$
*/
public class ListUtils {
@@ -65,6 +57,7 @@ public class ListUtils {
* Returns a new list containing all elements that are contained in
* both given lists.
*
+ * @param <E> the element type
* @param list1 the first list
* @param list2 the second list
* @return the intersection of those two lists
@@ -101,6 +94,7 @@ public class ListUtils {
* contains one occurrence, then the returned list will still contain
* one occurrence.
*
+ * @param <E> the element type
* @param list1 the list to subtract from
* @param list2 the list to subtract
* @return a new list containing the results
@@ -121,6 +115,7 @@ public class ListUtils {
* Returns the sum of the given lists. This is their intersection
* subtracted from their union.
*
+ * @param <E> the element type
* @param list1 the first list
* @param list2 the second list
* @return a new list containing the sum of those lists
@@ -135,6 +130,7 @@ public class ListUtils {
* first list. The {@link List#addAll(Collection)} operation is
* used to append the two given lists into a new list.
*
+ * @param <E> the element type
* @param list1 the first list
* @param list2 the second list
* @return a new list containing the union of those lists
@@ -212,15 +208,15 @@ public class ListUtils {
* @param list the list to generate the hashCode for, may be null
* @return the hash code
*/
- public static <E> int hashCodeForList(final Collection<E> list) {
+ public static int hashCodeForList(final Collection<?> list) {
if (list == null) {
return 0;
}
int hashCode = 1;
- Iterator<E> it = list.iterator();
+ Iterator<?> it = list.iterator();
while (it.hasNext()) {
- E obj = it.next();
+ Object obj = it.next();
hashCode = 31 * hashCode + (obj == null ? 0 : obj.hashCode());
}
return hashCode;
@@ -235,6 +231,7 @@ public class ListUtils {
* case the cardinality is zero. This method is useful if you do not wish to modify
* the collection <code>c</code> and thus cannot call <code>collection.retainAll(retain);</code>.
*
+ * @param <E> the element type
* @param collection the collection whose contents are the target of the #retailAll operation
* @param retain the collection containing the elements to be retained in the returned collection
* @return a <code>List</code> containing all the elements of <code>c</code>
@@ -262,6 +259,7 @@ public class ListUtils {
* case the cardinality is zero. This method is useful if you do not wish to modify
* <code>collection</code> and thus cannot call <code>collection.removeAll(remove);</code>.
*
+ * @param <E> the element type
* @param collection the collection from which items are removed (in the returned collection)
* @param remove the items to be removed from the returned <code>collection</code>
* @return a <code>List</code> containing all the elements of <code>c</code> except
@@ -298,6 +296,7 @@ public class ListUtils {
*
* This method uses the implementation in the decorators subpackage.
*
+ * @param <E> the element type
* @param list the list to synchronize, must not be null
* @return a synchronized list backed by the given list
* @throws IllegalArgumentException if the list is null
@@ -311,6 +310,7 @@ public class ListUtils {
* <p>
* This method uses the implementation in the decorators subpackage.
*
+ * @param <E> the element type
* @param list the list to make unmodifiable, must not be null
* @return an unmodifiable list backed by the given list
* @throws IllegalArgumentException if the list is null
@@ -327,6 +327,7 @@ public class ListUtils {
* It is important not to use the original list after invoking this method,
* as it is a backdoor for adding invalid objects.
*
+ * @param <E> the element type
* @param list the list to predicate, must not be null
* @param predicate the predicate for the list, must not be null
* @return a predicated list backed by the given list
@@ -350,6 +351,7 @@ public class ListUtils {
* Existing entries in the specified list will not be transformed.
* If you want that behaviour, see {@link TransformedList#transformedList}.
*
+ * @param <E> the element type
* @param list the list to predicate, must not be null
* @param transformer the transformer for the list, must not be null
* @return a transformed list backed by the given list
@@ -369,20 +371,21 @@ public class ListUtils {
* For instance:
*
* <pre>
- * Factory factory = new Factory() {
- * public Object create() {
+ * Factory<Date> factory = new Factory<Date>() {
+ * public Date create() {
* return new Date();
* }
* }
- * List lazy = ListUtils.lazyList(new ArrayList(), factory);
- * Object obj = lazy.get(3);
+ * List<Date> lazy = ListUtils.lazyList(new ArrayList<Date>(), factory);
+ * Date date = lazy.get(3);
* </pre>
*
- * After the above code is executed, <code>obj</code> will contain
+ * After the above code is executed, <code>date</code> will contain
* a new <code>Date</code> instance. Furthermore, that <code>Date</code>
* instance is the fourth element in the list. The first, second,
* and third element are all set to <code>null</code>.
*
+ * @param <E> the element type
* @param list the list to make lazy, must not be null
* @param factory the factory for creating new objects, must not be null
* @return a lazy list backed by the given list
@@ -396,8 +399,9 @@ public class ListUtils {
* Returns a fixed-sized list backed by the given list.
* Elements may not be added or removed from the returned list, but
* existing elements can be changed (for instance, via the
- * {@link List#set(int,Object)} method).
+ * {@link List#set(int,E)} method).
*
+ * @param <E> the element type
* @param list the list whose size to fix, must not be null
* @return a fixed-size list backed by that list
* @throws IllegalArgumentException if the List is null
@@ -412,6 +416,7 @@ public class ListUtils {
* If the input List or predicate is null, or no element of the List
* matches the predicate, -1 is returned.
*
+ * @param <E> the element type
* @param list the List to search, may be null
* @param predicate the predicate to use, may be null
* @return the first index of an Object in the List which matches the predicate or -1 if none could be found